Lower fetal heart rate variability and parenting stress associate with toddler psychopathology risk

Variations in fetal heart rate variability (HRV) may serve as early indicators of risk for later psychopathology. These individual differences could further interact with the postpartum environment to shape developmental outcomes. The present study investigated the relation between fetal HRV and toddler psychopathology in the context of postnatal parenting stress as an index of infants' early parenting environment. Mother-infant dyads (N = 159) were followed from the third trimester through 18 months postpartum. Fetal HRV was collected remotely during a 20-minute baseline at 34-40 weeks' gestation. Parents reported on parenting stress at 7 months, and toddler socioemotional outcomes at 18 months using questionnaires. Fetal HRV was not significantly associated with internalizing or externalizing problems alone. Parenting stress was positively associated with internalizing problems, but no interaction with fetal HRV was found. However, a significant interaction emerged for externalizing problems: lower fetal HRV predicted greater externalizing symptoms at higher levels of parenting stress. This study is among the first to investigate if interactions between fetal HRV and the postpartum caregiving environment associate with toddler transdiagnostic risk. These results highlight parenting stress as a promising intervention target, especially for babies with lower fetal HRV who may be at greater risk for psychopathology.